About that 'radioactive cloud'
My SO has a degree in nuclear engineering. He is explaining to me the issue with the nuclear reactor problem.
First, the core of the reactor is intact. This is encased in six inches of steel and is fine.
However what happened is that one of the pumps in the cooling system broke. This causes tons of steam and gunk to fly up in the air.
What appears to have happened, is a tritium release - this is not unusual considering what happened. The whole nuclear plant is on a platform so the core is not harmed by the earthquake.
In some (older?) power plants, the rods are suspended at the top, and are allowed to shake when there's an earthquake. The amount of power that they generate can fluctuate a little, but this is one approach to keeping the core safe. Each plant has a way to deal with geo-stresses and changes. The focus there, is preserving the core - that's the most important thing to do.
And that worked, in Japan.
BUT....What happens is that there are trace amounts of tritium in the hydrogen gas and water used in the plant. There are always trace amounts of tritium in any water.
When there is a failure in the coolant system, this titrium, which is (already) an isotope (a compound with 1+ extra neutron/different molecular weight), this tritium gets excited by the energy near it, in the core. Tritium has two extra neutrons. So when it gets close to other energy, its neutrons and then everything in that atom, get to rattling around very excitedly.
And then, it gets UN-excited, when it lets off its energy. It lets off its energy in the form of gamma radiation.
My SO thinks that after the de-energization(release of energy), that the danger from tritium is over. The key is, that you don't want that release to damage anything in the core of the plant. So it's important to release it, in a controlled way. You don't want to make any drastic sudden changes but you do want to gently reduce pressure.
In other words, these trace amounts of tritium in the water and gas, pick up energy, and then it release it.
For example, at Three Mile Island, there was a tritium release when they had their coolant system fail, but they managed it very carefully by slowly venting it and that protected the core. I don't know if the amount in the Japan plant is similar to the amount in the TMI plant release - probably that won't be reported for a while because they have to do a lot of eval first.
Radiation is a bad word, but in this case, the danger is very limited. The plant workers are in danger, certainly. Burns can be very serious. Neutron type damage tends to not go deep but it really burns.
And when this happens sea water is very good for cooling the system. Most plants are built near a water source so they can suck up a lot of water if they have to.
This sort of radiation is a threat to people in the plant who could take in a great deal of it right up close.
This is NOT a long term threat or a danger as it dissipates. The half life on tritium is very short.
Don't tell me I'm pro-nuclear - I'm not. I'm just giving facts. This sort of release is not of widespread danger.
